396710 - Compiling nsAppShell.mm results in cast error

Status: RESOLVED FIXED

(Core :: Widget: Cocoa, defect)

Description

[Ed Lee :Mardak]

The following line has an error about not being able to cast const NSA* to NSA*.
+  NSAutoreleasePool* pool = static_cast<const NSAutoreleasePool*>

Probably introduced by bug 348748
http://hg.mozilla.org/cvs-trunk-mirror/?diff/ab58bdbde9e0/widget/src/cocoa/nsAppShell.mm

Changing pool to type const NSAutoreleasePool * seems to compile even with the "[pool release];" below.

I just switched over to gcc4 instead of gcc3.3 last night and ran into this issue.

Comment 1

[Ed Lee :Mardak]

Attachment: v1

Comment 2

[Steven Michaud [:smichaud] (Retired)]

Actually I'd prefer to fix the problem this way:

-  NSAutoreleasePool* pool = static_cast<const NSAutoreleasePool*>
+  NSAutoreleasePool* pool = static_cast<NSAutoreleasePool*>
                                        (::CFArrayGetValueAtIndex(mAutoreleasePools,
                                                                  count - 1));

As far as I can tell, there's no reason to use "const" in the cast.

Comment 3

[Ed Lee :Mardak]

(In reply to comment #2)
> As far as I can tell, there's no reason to use "const" in the cast.

widget/src/cocoa/nsAppShell.mm:399: error: static_cast from type 'const void*' to type 'NSAutoreleasePool*' casts away constness

Comment 4

[Steven Michaud [:smichaud] (Retired)]

Comment on attachment 281480 [details] [diff] [review]
v1

> widget/src/cocoa/nsAppShell.mm:399: error: static_cast from type 'const void*'
> to type 'NSAutoreleasePool*' casts away constness

Oh, well.

Then your patch looks fine to me as it stands ... though I haven't
tested it myself.

Comment 5

[Mark Mentovai]

Comment on attachment 281480 [details] [diff] [review]
v1

The indentation on the continuation lines is starting to look heinous here.  Please fix.

Comment 6

[Ed Lee :Mardak]

Attachment: v1.1

Combined the 2nd and 3rd line and shifted indent left.. which makes it line up nicely with the 4th.

But I wonder why other people aren't running into this compilation error.. ?

Comment 7

[Steven Michaud [:smichaud] (Retired)]

> But I wonder why other people aren't running into this compilation
> error.. ?

What results do you get from running gcc_select?

If it returns '3.3' (or anything but '4.0'), try switching to '4.0'
(you'll need to use sudo).

Comment 8

[Ed Lee :Mardak]

I actually got the error switching /to/ 4.0. I am using a PowerPC iBook though.

$ gcc-3.3 -v
Reading specs from /usr/libexec/gcc/darwin/ppc/3.3/specs
Thread model: posix
gcc version 3.3 20030304 (Apple Computer, Inc. build 1809)

$ gcc-4.0 -v
Using built-in specs.
Target: powerpc-apple-darwin8
Configured with: /private/var/tmp/gcc/gcc-5026.obj~19/src/configure --disable-checking --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^+.-]*$/s/$/-4.0/ --with-gxx-include-dir=/include/gcc/darwin/4.0/c++ --build=powerpc-apple-darwin8 --host=powerpc-apple-darwin8 --target=powerpc-apple-darwin8
Thread model: posix
gcc version 4.0.0 (Apple Computer, Inc. build 5026)

Comment 9

[Steven Michaud [:smichaud] (Retired)]

I'm stumped.

The only other thing I can suggest is that you need to rebuild from
scratch whenever you switch gcc versions.

Your developer tools seem a bit old, though -- my gcc 4 version is
actually 4.0.1 (and the build number is 5250).

(By the way I build on both PPC and Intel (using gcc 4.0.1 in both
cases), and I've never seen a cast _error_ ... though I might have
missed a warning.)

Comment 10

[Ed Lee :Mardak]

Comment on attachment 281902 [details] [diff] [review]
v1.1

Do we want this for 1.9?

I downloaded the latest Xcode which updated g++ to 4.0.1 build 5367, and I don't get the cast error even without this patch.

Comment 11

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 281902 [details] [diff] [review]
v1.1

might as well have this

Comment 12

[Ed Lee :Mardak]

Checking in widget/src/cocoa/nsAppShell.mm;
/cvsroot/mozilla/widget/src/cocoa/nsAppShell.mm,v  <--  nsAppShell.mm
new revision: 1.24; previous revision: 1.23
done